How to do something only once, ever

Question

I am writing a script that downloads some files and executes them. I only want each filename executed once by the hosts that are downloading them. I am trying to create a script that pulls the files, executes them if they havent already been executed, and then keeps track of each file that has been executed to prevent duplicate runs. So far all I seem to be able to do is execute all each time, and the backup record does not trigger the deletion of the duplicates.

(cd /opt/trunk/mythos/medusa/remote-scripts/ && wget -r --no-parent --reject "index.html*" http://server/medusa/scripts/)
chmod +x /opt/trunk/mythos/medusa/remote-scripts/server/medusa/scripts/*.sh
for each in /opt/trunk/mythos/medusa/remote-scripts/server/medusa/scripts/*.sh
do
    if /usr/bin/test -e $each.bak
    then
        rm -rf /opt/trunk/mythos/medusa/remote-scripts/server/medusa/scripts/$each
    fi
    bash $each
    mv $each $each.bak
done

What am I doing wrong?

Answer 1

Put bash $each and mv $each $each.bak in an else block:

(cd /opt/trunk/mythos/medusa/remote-scripts/ && wget -r --no-parent --reject "index.html*" http://server/medusa/scripts/)
chmod +x /opt/trunk/mythos/medusa/remote-scripts/server/medusa/scripts/*.sh
for each in /opt/trunk/mythos/medusa/remote-scripts/server/medusa/scripts/*.sh
do
    if /usr/bin/test -e "$each.bak"
    then
        rm -rf "/opt/trunk/mythos/medusa/remote-scripts/server/medusa/scripts/$each"
    else
        bash "$each"
        mv "$each" "$each.bak"
    fi
done

That way the current script will be executed and moved only if /usr/bin/test -e "$each.bak" fails (i.e. the current script hasn't been executed and moved previously).

I quoted all the variables with double quotes to prevent them from breaking the commands in case they end up containing weird characters / strings.